sidicks:
Boxster Coupe GTS:
Yes, the 991 GT3 RS with optional manual gearbox will indeed be faster than the 991 GT3 PDK!
Keep in mind the 991 GT3 RS will have inter alia more power, less weight, increased downforce, rear wheel steering...
For example, if you take a 997 GT3 RS 4.0 with the traditional Mezger engine and manual gearbox and just fit it with the latest generation cup tyres (Michelin Pilot Sport Cup 2 or Dunlop Sport Maxx Race) it can already lap as fast as the 991 GT3 PDK -- and that's without the advantages of the new 991 chassis, RWS, etc.
The 991 GT3 was benchmarked to outperform the 997 GT3 RS 3.8 with a target Nurburgring lap time below 7m30s.
The 991 GT3 RS is benchmarked to outperform the 997 GT3 RS 4.0 with a target Nurburgring lap time around 7m20s.
The idea that Porsche is unable to make a 991 GT3 RS with a manual gearbox that's faster than the 997 GT3 RS 4.0 gives very little credit to the motorsport engineers in Weissach... the 991 GT3 RS will establish a new benchmark!
As an aside, at the Frankfurt Motor Show the new Lamborghini Gallardo will be unveiled with a manual gearbox (also available on the next generation Audi R8) -- Porsche are understandably keen to maintain an appropriate range of GT models for cater for both new PDK drivers and their existing GT3 and GT3 RS customer base.
It's not that they CAN'T do it, it's whether it is economically sensible for them to do so.
I had some "inside information" on the 991 GT3 development but not the 991 GT3RS. Its been discussed on other boards. The only information I have here is that the architecture was already set months ago around the time of the GT3 launch. At that time the RS was PDK only.
The 991 GT3 has already surpassed the 4.0RS in terms of 0-100 and Ring time (for the 4.0RS 3.8s and 7.27 respectively). That was using Dunlop Sport Maxx tyres and it was not the fastest run achieved - more a median of fast runs. This part I know for 100%. The new MPSC2 tyres could provide another .1-.2s in ideal conditions over the Dunlops according to teh engineers (they appear to be a better warm/dry tyre and the Dunlops a bit better in the wet) although AP says they are both about the same performance.
The RWS is independant of the gearbox. It is however integrated into the "network" via the ECUs which have Yaw sensors. RWS can be made to work with MT gearbox but would need calterations to lectronics/network.
Ive spent the last half a day looking at track traces from a track day this weekend using manual 911 and I can say without doubt on a circuit as long as the Ring the PDK must be saving 3-4s in shift times. If I run my local 3km circuit and make two less shifts it saves me 0.33s alone. Thats a 1.20s course. The time taken to shift manually creates a blip in the trace where acceleration is momentarily retarded. If the ring had say 50-60 sift points in a manual not only would these likely to be reduced by 20-30% with PDK but also the speed of the PDK shift would save another 35-35% time wise for those shifts that do occur. And thats with a professional driver so PDK is definately an advantage at the Ring. This is one of the benefits the Nissan GTR had over the GT3 previously given in pure power terms its only 100 bhp more (2009-2011 model) but weights almost 200kg more and posted times in the mid 7.20s
The PDK gearbox isnt just about shift times on the track its about stability, balance and also optimal shifting (getting the shiftpoint right to maximise the ratio between HP and Torque.
The 991 GT3 RS will not be massively lighter than the 991 GT3 for reasons already stated. It will also unlikely have a significantly higher top speed. This is due to the even wider Turbo body. the Turbo/S factory quotes top speed are only 1-3mph higher than the 991 GT3 for similar reasons even with higher power to weight ratio.
The 991 GT3 is likely to stay at 3.8L. The specific output will not move significantly as they at most can change Cam, inlet manifold, airbox and exhaust configurations. they are more likely to use some of the unquoted power the 991 GT3 already makes but doesnt publish with some small tweaks on the aforementioned perhaps another 15bhp for a headline figure of 500bhp.
Getting the new manual gearbox ready for the 991 GT3RS this generation would be a huge task for the development team given the car launches in less than two months. The MT project was largely shelved back in November 2012 and would require the engineering of a second dedicated hydrallic pump to run the e-diff. Its possible to do as other manufacturers have done this but its not an overnight solution. The entire engine management system and networked ECUs will also need to be recalibrated (traction control and others).
For these reasons its highly unlikely the 991 GT3 RS will be launched in Sept in MT. Apart from the above reasons there is also the point RC mentioned which put simply is that Porsche have made a commitment here and would be accepting defeat before the worlds motoring press and their customers have even had a 991 GT3 to test properly on road and track. I just dont see that happening Im afraid.
Lastly, even in the specification I state below I believe the 991 GT3RS would be about the same around the Ring than the 991 GT3. For example if you were to make the 991 GT3 manual I would suggest Ring time would fall back to 7.29 so Id suggest around 7.24-7.25. To pay 30k more for no better headline figures would be difficult for many.
My take on the 991 GT3 RS (and you can hold me to this) would be
PDK only
RWS
3.8L 500 bhp (stated), 330 lbft torque
0-100 in 3.2s
Ring time around 7.20
Weight 1395-1405kg (assumes fixed bucket seat available). More composites, less interior furniture. Remember + half cage too (20kg).
Turbo wide body, 20" CL wheels (lighter weight again over GT3)
You must remember the 997.1 GT3/RS had no difference in power/engine only suspension and small weight and this is where I think we will be going again with the 991 GT3RS. Graphics yes, extra large wing yes, some additional body adornments yes, big power increase = no IMO.
Of course this is mostly speculation and shortly we will know for sure, but I certainly wouldnt be getting my hopes up for MT. Given the lack of number of 991 GT3RS test mules that have been pictured testing so close to launch time Id suggest the base architectture is already set in stone and we are looking at mostly styling changes and some suspension and wheel tweaks...of course Id love to be wrong but I dont think Ill be far off the mark....